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In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.

Passage: Thado Minbya was born Rahula to Princess Soe Min Kodawgyi of Sagaing and Viceroy Thado Hsinhtein of Tagaung in 1345. From his mother's side, he was a grandson of King Saw Yun, the founder of the Sagaing Kingdom, and nephew of then reigning king Kyaswa as well as a great grandson of King Thihathu of Pinya and King Kyawswa of Pagan. From his father's side, he was descended from a line of hereditary rulers of Tagaung from the House of Thado. According to British colonial period scholarship, his father was an ethnic Shan and his mother was mostly Shan; however some have argued that no extant chronicle or archaeological evidence supports the conjecture. The prince had two younger sisters: Shin Saw Gyi and Saw Omma. His father died soon after the birth of Saw Omma. His mother remarried to Thihapate, a grandnephew of Queen Pwa Saw of Pagan. In 1352, Thihapate became king of Sagaing.
 Link Information: After Thihathu's death in 1325, the two kingdoms formally went separate ways, with Pinya controlling southern Upper Burma and Sagaing northern Upper Burma. (Zatadawbon Yazawin and Maha Yazawin chronicles count Saw Yun's official reign at Sagaing only after the death of Thihathu whereas later chronicles Yazawin Thit and Hmannan Yazawin count his reign from his first insurrection in 1315.) Early on, Pinya's new rulers still had designs on Sagaing. Pinya's attempt to assassinate Saw Yun nearly succeeded, stopped only by the assassin Khin Nyo's conscience at the last minute.

Saw Yun was remembered in Burmese chronicles as powerful, kindly and popular. He also contributed to Burmese military. In 1318, Saw Yun formed a cavalry regiment called Sagaing Htaungthin ( ; lit. "Thousand-strong Regiment of Sagaing", although the numbers added up to only 830), which was maintained up till the fall of Burmese monarchy, and nine squadrons of cavalry.

He died 5 February 1327. Question: How long was the reign of Minbya's grandfather?
Output:
Answer: 2